var banner = new Array();

banner[0]='http://img135.imageshack.us/img135/9176/banner1pg.png/';
banner[1]='http://img840.imageshack.us/img840/6121/banner2gh.png';
banner[3]='http://img824.imageshack.us/img824/8104/banner3m.png';
banner[4]='http://img135.imageshack.us/img135/9176/banner1pg.png/';
banner[5]='http://img840.imageshack.us/img840/6121/banner2gh.png';
banner[6]='http://img824.imageshack.us/img824/8104/banner3m.png';

document.getElementById('i_logo').src= banner[Math.floor(Math.random()*banner.length)];

setInterval("document.getElementById('i_logo').src= banner[Math.floor(Math.random()*banner.length)];",120000);